[Extensive tinea corporis due to a terbinafine-resistant Trichophyton mentagrophytes isolate of the Indian genotype in a young infant from Bahrain in Germany]

Abstract

A 6 month-old-female infant from Bahrain visiting Germany with her family for a holiday was seen by us for extensive dermatophytosis of the back, buttocks, chest and groins. Topical treatment by terbinafine for over 2 months was not successful. Other family members including adults and children were treated in Bahrain with topical antifungals and oral voriconazole which was not helpful. Mycological examination performed in Germany revealed the detection of the zoophilic dermatophyte Trichophyton (T.) mentagrophytes. The newly described genotype VIII within the species T. mentagrophytes was identified by sequencing of the "internal transcribed spacer" (ITS) region of the fungal rDNA. This genotype of T. mentagrophytes is the main causative agent of the current epidemic of chronic recalcitrant dermatophytoses in India. Transmission of this Indian genotype of T. mentagrophytes to other countries due to globalization is a serious issue to be considered. Moreover, a significant percentage of these Indian T. mentagrophytes strains are resistant to terbinafine both in vitro and by the way of genetic point mutations in the squalene epoxidase (SQLE) gene. Some are also found to be partially resistant against itraconazole and voriconazole. The point mutation TTC/TTA was found by SQLE mutation analysis in this particular T. mentagrophyte isolate from Bahrain. This point mutation is closely associated with F397L amino acid substitution of the enzyme indicative of in vitro resistance of the dermatophyte against terbinafine. The girl was successfully treated by topical miconazole and later by ciclopirox olamine. This is the first report on an infection due to a terbinafine-resistant T. mentagrophytes strain of the ITS genotype VIII from India in Germany.

Keywords: Ciclopirox olamine; Dermatomycoses; Miconazole; Mutation analysis; Point mutation.